Temperature Mapping

BRIC uses Magnetic Resonance Spectroscopic (MRS) to collect data used to estimate temperature on a voxel by voxel basis.

Temperature estimation is based on the known temperature dependence of the water resonance frequency. The dependence is very small at 0.01ppm per degree C, but can nevertheless be detected in MRS data sets.

Researching activity measuring heat in brain tissues:

BRIC carried out retrospective analysis of MRS data from 40 stroke patients. By combining data from several voxels from each patient, we showed that regional temperatures vary within the ischaemic lesion. Referring to the diagram below, the acute ischaemic stroke lesion is marked in red (left hand side), which shows the corresponding temperature within the lesion being variable.

Above figure: (a) diffusion-weighted image and (b) corresponding temperature map of a patient with an acute ischaemic stroke lesion in the left parietal region. In (b), the lesion outline is shown in red. Temperature scale in degree C.

Researching activity measuring coolness in brain tissues:

Members of the BRIC team have also been keen to work alongside the Brain Cooling team, to assess whether reducing the temperature of injured brain tissue can help protect it from further damage. Prof Macleod is leading a trial testing a new device, Brain Cool Dignicap. This is a silicon cap and neck collar with fluid channels of cooling fluid which lowers the scalp temperature and blood in the neck (Fig 3). This is already a technique well established for the prevention of chemotherapy induces hair loss. As therapeutic hypothermia is a promising treatment for stroke and traumatic brain injury, this trial hopes to be able to cool deeper brain tissue in awake volunteers. If successful this could potentially lead to brain-cooling treatment being available in ambulances.

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